[LU-16688] Client crash due to an assertion in lite_lib.c:3394

• Status: Resolved
• Project: Lustre
• Type: Bug
• Priority: Critical
• Reporter: Tao Lyu
• Assignee: Zhenyu Xu
• Resolution: Fixed

Environment

Three server nodes and one client. Kernel version: Ubuntu-5.4.0-90.101

1. MGS
   mkfs.lustre --fsname=lustre --mgs /dev/vda
   mount -t lustre /dev/vda /root/lustre-server

1. MDS
   mkfs.lustre --fsname=lustre --index=0 --mgsnode=$start_ip@tcp0 --mdt /dev/vda
   mount -t lustre /dev/vda /root/lustre-server

1. OSS
   mkfs.lustre --ost --fsname=lustre --index=1 --reformat --mgsnode=$start_ip@tcp0 /dev/vda
   mount -t lustre /dev/vda /root/lustre-server

1. Client
   mount -t lustre $start_ip@tcp0:/lustre /root/lustre-client

• Severity: 3

Description

PoC:

int fd = open(".", 0, 0);
ioctl(fd, 0xc00866a4, 0);

Stack trace:

LustreError: 54949:0:(llite_lib.c:3394:ll_obd_statfs()) ASSERTION( data ) failed: 
LustreError: 54949:0:(llite_lib.c:3394:ll_obd_statfs()) LBUG
Kernel panic - not syncing: LBUG
CPU: 0 PID: 54949 Comm: syz-executor Tainted: G           O      5.11.22+ #46
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-1ubuntu1.1 04/01/2014
Call Trace:
 dump_stack+0x57/0x6a
 panic+0x151/0x312
 lbug_with_loc.cold+0x2c/0x2c [libcfs]
 ll_obd_statfs+0x116b/0x1850 [lustre]
 ll_dir_ioctl+0x60ce/0x1aa90 [lustre]
 __x64_sys_ioctl+0x83/0xb0
 do_syscall_64+0x33/0x40
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x7ffff7389aad
Code: 02 b8 ff ff ff ff c3 66 0f 1f 44 00 00 f3 0f 1e fa 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffff40bf7b8 EFLAGS: 00000212 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007ffff73e041f RCX: 00007ffff7389aad
RDX: 0000000000000000 RSI: 00000000c00866a4 RDI: 0000000000000003
RBP: 00007ffff40bf810 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000212 R12: 00007fffffffe0de
R13: 00007fffffffe0df R14: 00007fffffffe180 R15: 00007ffff40bfd80
Kernel Offset: disabled
---[ end Kernel panic - not syncing: LBUG ]---

Issue Links

• is related to: LU-16634 Null pointer dereference in lustre_se...
• is related to: LU-16890 allow OBD_FREE() to ignore NULL pointers

Comments

[Andreas Dilger]

Hello tao.lyu, what version of Lustre is this running?

I don't see an LASSERT(data) in ll_obd_statfs(), nor anywhere in the client code, though it is possible that it is hidden behind a macro somewhere.

Is this running the patches from LU-16634? Those should preferentially be used for your future testing, so that we don't get duplicate bug reports for the same NULL-argument ioctl calls.

[Gerrit Updater]

"Zhenyu Xu <[e-mail]>" uploaded a new patch: https://review.whamcloud.com/c/fs/lustre-release/+/50484
Subject: LU-16688 llite: avoid free empty pointer
Project: fs/lustre-release
Branch: master
Current Patch Set: 1
Commit: 17d346e669fddb03aba60c9fc31fb75c46dd893c

[Zhenyu Xu]

fixed in LU-16890